Jones v. Mayer clearly established for the first time Congress' right to prohibit discrimination in purely private matters. In so doing, the Court skirted the highly questionable value of the Fourteenth Amendment on the issue, and instead opted for an even more peculiar reading of the Thirteenth.

Jones charged that the private defendants had refused to sell him a house because he was black. In bringing his suit, he pointed to a portion of the Civil Rights Act of 1866, subsequently Title 42 Section 1982 of the U.S. Code, which guarantees all citizens equal rights to purchase property. The purpose of this portion of the Act was to invalidate southern state statutes which made it difficult or impossible for blacks to buy or lease property. In invalidating such statutes, the Act did exactly what the Fourteenth Amendment was intended to do two years later.

In the instant case, however, the Court saw that applying the Fourteenth to such a purely private matter would be without significant precedent and constitutionally difficult. Instead they fell back on an opinion in the Civil Rights Cases (1883), wherein it was stated that under the Thirteenth Amendment (ending slavery), Congress may outlaw not only slavery, but the manifestations of slavery as well. It left it to Congress to define those manifestations. By extension, the Court affirmed Congress' right to apply Section 1982 to private behavior as a manifestation of past slavery.

Simultaneously, the Court invalidated the Civil Rights Act of 1875, which had banned discrimination in public accommodation, but specifically avoided infringing private rights.

The soft constitutional foundations upon which the Jones decision was supported were revisited in a variety of future cases, though never overturned. In Runyon v. McCrary (1976), the Court extended the Jones logic to Title 42 Section 1981, which prohibited discrimination in contracts. Between the two decisions, vast Congressional power over private rights of property and contract, as regards discrimination, were established.

Lingering doubts about the validity of both decisions, and changes in the Court's make-up, caused it to tangle the Runyon decision a bit in 1989, when it decided in Paterson v. McLean Credit Union that Section 1981 only applied to the initial decision to contract, not to actions taken thereafter.

However, Congress has been quite happy with the power granted to it by the two decisions, and reaffirmed its Section 1981 powers in the Civil Rights Act of 1991, specifically including post-contractual behavior.